1. Field
Embodiments of the present invention relate to a display device in which a driving voltage is supplied to red, green, and blue subpixels through two power supply lines.
2. Description of the Related Art
In general, flat panel displays (FPDs) such as liquid crystal display (LCD) and organic light emitting diode (OLED) display include a pair of electric field generating electrodes and an electro-optical active layer interposed therebetween. In the case of the LCD, a liquid crystal layer is included as the electro-optical active layer, and in the case of the OLED display, an organic light emitting layer is included as the electro-optical active layer.
One of the pair of electric field generating electrodes is generally coupled to a switching element so as to receive an electric signal. The electro-optical active layer converts the electric signal into an optical signal so that an image is displayed.
The FPDs use a thin film transistor (TFT), which is a three-terminal device, as the switching element, and may include signal lines such as a gate line to transmit scan signals in order to control the TFT and a data line to transmit signals to be applied to a pixel electrode.
However, recent display devices with large area and high integration result in IR drop, and the IR drop causes luminance non-uniformity of the display devices. For instance, in the case of digital driving, unlike analog driving, driving voltage is directly applied to a pixel electrode of the display device when a pixel emits light. Therefore, a variation of the driving voltage causes a variation of voltage of the pixel electrode of the display device, and this results in luminance non-uniformity of the display device. In the digital driving method, different voltages are supplied to a red subpixel, a green subpixel, and a blue subpixel in order to maintain uniform luminance. Accordingly, power supply lines are located in the red subpixel, the green subpixel, and the blue subpixel, respectively, such that the display device has a low aperture ratio.